1. Field of the Invention
The present invention relates to a display and a method of driving the display.
2. Description of the Related Art
A liquid crystal display is one of various types of display devices. In a liquid crystal display, liquid crystal material is interposed between two substrates having electrodes thereon, and different voltages are applied to the two substrates to generating an electric field, so that alignment of the liquid crystal molecules is controlled. Accordingly, light transmissivity is controlled, whereby the liquid crystal display displays images.
The liquid crystal display includes a plurality of pixels in which a pixel electrode, red R, green G and blue B color filters are formed. The pixels are driven by control signals supplied through signal lines to display images. The signal lines include a gate line through which gate signal (or scan signal) is transmitted, and a data line through which data signal (or grayscale signal) is transmitted. A thin film transistor connected to one gate line and one data line is disposed in each pixel. The voltage level of the data signal is changed according to image data, and the gate signal is used to turn on or off the thin film transistor. The data signal is supplied to the pixel electrode to charge the pixel while the thin film transistor is turned on, so that the transmissivity of liquid crystal is controlled and desired images are displayed.
The gate signal (or gate voltage) and the data signal (or data voltage) are supplied through a gate driving chip connected to the respective gate lines and a data driving chip connected to the respective data lines. In general, the data driving chip includes a more complicated inner circuit compared to the gate driving chip. Current consumption of the data driving chip is therefore generally larger than that of the gate driving chip. In addition, as a demand for displays having fine pitch and high resolution has increased recently, the number of required pixels and an amount of image data to be processed has also increased. For this reason, current consumption of the data driving chip is also increasing rapidly. For example, a liquid crystal display of a full high definition (FHD) grade which is of current interest, requires a processing ability for image data having much higher bits (about 8 bits or more) compared to a conventional liquid crystal display. For this reason, the current consumption of the FHD liquid crystal display has increased. Further, in some liquid crystal displays, pixels are driven at a frequency of 120 Hz, which is about twice the typical frequency, in order to increase the response speed. The time allocated for charging the data signal is thus reduced due to the high speed driving. Thereby, bias current of the data driver needs to be increased to attain a desirable display quality. As a result, the current consumption is increased. Further, malfunction of the chips is more likely due to a heat generation caused by the increased current consumption, so that the chips are damaged resulting in a higher defect ration for the displays.